3mm to 1.75mm rework extruder

Just wondering, after seeing the developments of the Filabot, would it be easy to make a small extruder that can rework 3mm filament into 1.75mm for us brits which have to pay extortionate amount for thinner filament? Surely since the plastic is already in rod form there wont be the issues of compressing and removing air from it before extrusion and we already have pretty decent extruder for making very thin diameter filament.

Just a thought really, i know I dont have time to develop one but I know I'd get/make one if it was cost effective and allowed me to print 1.75mm at minimal expense.

I would suggest extruding into a length of teflon/ptfe tube that runs through a water bath. The real trouble would probably be the coiling of the extruded plastic. Also the heat transfer needs to be pretty high if you want to "convert" a substantional amount of 3mm filament into 1.75mm filament.
Pesonally i was thinking about extruding plumbing ABS (40mm tube) into 3mm filament. By weight the filament is still much more expensive than abs sold for plumbing and plumbing abs is available anywhere.

Thats an idea, I though that solid filament would avoid the need to pressurisation to remove air from inside the filament. Surely if you use a pipe then you would need to remove the possibility of trapped air inside the filament once it's extruded. or am I missing something? Also trying to cool and insulator might be quite hard, what other materials have low friction but high heat transfer properties that the filament could pass through to cool down?

It would be neat if we could reform cheaper abs into usable filament and I think that although the goal should be recycling old filament, at this point just reducing the cost significantly would be very welcome.

If you want to produce 1.75mm filament from 3mm it might be easier to reform it with heated rollers rather than re-extruding it.

TC

Why not just use 3mm filament if it is so much less expensive?

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Some people see advantages in 1.75 mm filament that could help them going further down on the layer height scale.

The Ultimaker seems perfectly capable of printing .05mm layers with 3mm filament...

I can almost guarantee you will get worse results using re-extruded 1.75mm filament instead of the 3mm filament it was made from.

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www.Fablicator.com